Dial gauge



Jan. 18, 1949.

e. P. BosoMwoRTH DIAL GAUGE I 2 Sheets-sheaf 1 Filed June 29, 1945 Qrwwwbow GEORGE P. BOSOMWORTH G. P. BOSOMWORTH DIAL GAUGE Ja .n. 18, 1949.

'2 Sheets-Sheet Filed June 29, 1945 GEORGE l? BOSOMWORTH Patented Jan. 18, 1949 UNITED STATES PATENT OFFICE K, 2,459,749 v g I DIAL GAUGE (leorgev P. Bosomworth, Akron, ,Ohio', assignor to The Firestone Tire & Rubber Company, Akron, Ohio, a. corporation of Ohio 7, Application June 29,194 5, Serial No. 602,330; H

'2 claims. (01. sis-14?) This invention pertains togauging mechanism that is useful in the testing of cords-or other strands, and more especially it relates tomechanism for determining certain data with respect to the elongation characteristics of these cords or strands. It is contemplated that several cords will be tested at one time,-each of them being subjected to a test which is identical, so near as is practicable, to the test aplied to each'of the other cords. Preferably there is controlled temperature and humidity in the enclosure within which the greater part of each of the cords is housed.

While the invention is in no Way limited to the gauging of any particular type of cord or strand, it is especially useful when employed to test cords of various materials-such as cotton, rayon, nylon or any of the other strands or cords of animal, vegetable or synthetic materials. One example .of an instance in which datadetermined with this type machine may be useful is that pertain-- ing to cords to beempioyed in tires. It isa wellknown fact that tires, after a short period of use, grow or increase in size, this being attributed to the inability of the the cords tomain'tain a definite length. Apparently, these cords stretch or in some way increase their length after a rather short period of tire use,-and in the development of tires and in an attempt to' check this tire growth, the present apparatus is used to advantage.

Since the element of time is important so far as these tests are concerned, it is very desirable that extremely accurate measurements be taken at frequent intervals. To this end the dial gauge type of measuring instrument constituting the invention has been developed especially for use with this type of testing mechanism. Normally such gauges are so constructed that in using the gauge, an increasing resistance i brought into play as the central staff of the gauge ispressed inwardly, that is, the smaller the dimension to be measured, within the latitude provided by the instrument, the greater the resistance oflered by the instrument itseli. In measuring elongation of cords, such a gauge has been found to be of little use since, for short periods of time, the elongation to be measured is very minute. For accurate results a gauge of this general type. has been reconstructed in such a way that the amount of resistance oiiered to movement of the central s-tafi is extremely slight, and does not vary at any point throughout the entire travel or movement for which the instrument is: designed.

The invention will be described by reference-to 2- the preferred embodiment of the same shown in the accompanying figures of drawing of'which:

Fig.1 is a frontplan view of a section of the machine howing" cords being subjected to elongation and a dial gauge in place for taking a measurement;

Fig.2 is a detailed view of one of the lower cord clamping or retaining elements;

Fi 3 is a section at line 3-3, Fig. 2;

Fig. 4 is an elevation of the dial gauge of the invention;

Fig. 5' is a section of the dial gauge, double size, showing details ofthe entire mechanism; and

Fig. -6 is a die/metric section through the upper part of the dial gauge.

Now referring to Figs. 1, 2 and-3, the testing apparatus is generally constructed as an enclosure or casing having upper and lower compartments, the upper compartment, at least, being closed when desired and communicating with the lower compartment only by a series of rather small openings through which the cords or strands are threaded The upper compartment hasatop HI, back H and a central, dividing bulkhead 12 which is really the lower portion or floor of'theupper compartment, The upper compartment has doors (not shown) which close tightly against the ends, top section It] and a sill Hi. The lower compartment which is not necessarily to be enclosed has a back Maud a base IS, the latter being level and machined to present a smooth, true surface from which measurements may be taken.

The top section Ht has attached thereto for each of the cords a clamping device which consists of a depending lo'raclzet 'l'b from which projects a snubbing post I! about which a cord I 8 is wrappedfior two or three turns and having a clamp for securing the end of the cord as an adjusting or clamping screw [5- is tightened. The details of this clamp are similar to that of the lower" clamps such as shown in. Fig. 3 and which willhe described in greater detail in due course? g I The cord i8 is threaded down tthrough an eye- .liet or: opening 2c: in the bulkhead i2 and is in turn wrapped or snubbed; about the post 2! projecting outwardly" from asliding element,- generally in dicated by numeral 22, and which is in fact a combined card holder andweight carrier. The post 2! is grooved to receive the cord It in align ment with the opening, 20: s-otha't there will be no frictional contact .lc'etween that cord. and the sides of the opening. As. shown in. both. Figs; 2 and 3, thewcord, after around at ,Ieasta same is moved under the influence of a depending weight and as the cord or strand allows such movement by its elongation.

This sliding element 22 has: laterally projecta ing ears 28 and 29 which have holes therein accurately machined for engagement with the rods 26 and 21 thereby providing for true verticalmovement without any appreciable friction. The

ferent sizes or for different purposes, it may well be desired to provide a measuring instrument having a greater range. The outer portion of the face is indexed so that a pointer 44 rotatable on the central pivot 45, may indicate measurements to a thousandth of an inch. A smaller pointer 46 rotatable on pivot 41 shows tenths of an inch so that varition in elongation up to an inch may be indicated, the smallest increment of variation shown by this particular instrument being one thousandth of an inch. Of course,

smaller increments may be measured by an alteration in gearing and indexing.

.. Now referring to Fig. 5, the back of the case has been removed and part of plate 48 is cutit away. The central staff is in lower position and the same is guided in the bearings 49 and 50.

sliding element 22 also has a forwardly extending projection 30 to which is attached a rod 3| having av weight supporting disc or plate 32 on which is supported a, weight 33. Each of these rods 3| is held in position andisadjustable vertically by means of the large thin adjusting disc 34. This disc bears upon a washer 35 and a hex nut 36 may be used to lock the adjusting disc 34 in position.

Each of the rods 3| projects down through a guide 31 in a plate 38, said plate extending the length of the lower compartment and fastened to back l4. It can be seen that there is really a three point sliding arrangement for the combined cord clamping and weight carrying mechanism. Thus it is maintainedvertically in position and its movement as the cord extends under load, must-be in a true vertical direction and with as little friction as is practicably possible.

The top H] of the upper compartment, bulkhead l'2, plate 38 and the top machined surface of the base or floor l5 for the lower compartment are all horizontal and thus truly parallel to each other. That is important since when measurements are taken by a dial gauge or other measuring device, that gauge must slide along the machined surface which serves as a reference point or base from which accurate measurements may be taken. In setting up the machine for test purposes, cords are clamped in position so that each of the sliders 22 will be in practically the same horizontal plane, in other words, the initial set up is such that the same length of cord is to be tested at each station. By adjusting the rods 3| so that the lower ends thereof will initially show the same measurement on the gauge, the operator is thereby able to start the test with a common reading at each of the stations after which variations or elongation can be measured and directly compared to the initial indication.

Referring to Figs. 4, 5 and 6, an improved dial gauge embodying the invention is shown, said gauge being especially adapted for use in connection with cord testing apparatus hereinbefore described. The gauge generally includes a case 39 supported on a base 40-, a graduated face 4| and a central staff 42 at :the. end of which is a hardened contact element 43. The staff 42 is, of course, movable so that a measurement can be taken between the lower machined and ground surface of the base of the instrument and the end of the contact element 43. The range of movement for the staff and therefore the range through which measurements may be taken is, in this particular instance, one inch, but that is only byway of example andv in machines of dif- Rack teeth 5| are cut at one side of the staff 42 and those teeth mesh with similar teeth in a pinion 52 fixed to pivot 53 on which is also fixed a larger gear 54. The gear 54 meshes with a-small pinion 55-which is really cut on the spindle 45, centrally located, and which carries pointer 44. 4 A gear 56 fixed to the pivot or spindle 41 which carries the small pointer 46 has ten times as many teeth as are provided on pinion 55. As the staff 42 is moved vertically, the movement thereof is transferred through the gearing just described to the pointers 44 and 46. The ratio of this gearing and indexing is such that for a movement of one thousandth of an inch for the staff, pointer 44 will indicate that amount I of movement on the face of the instrument. The small pointer 46 receives one tenth of the angular movement imparted to -pointer 44 and thus for every hundred thousandths of an inch, that is, for each complete rotation of pointer 44, the small pointer will move one tenth of itscomplete arc of movement or will indicate one hundred thousandths or one tenth of an inch. In this way, a measurement-can betaken in which the pointer 44 makes.several revolutions on its dial or face, the number which it has made being indicated by the small pointer 44 and the graduae tions on the smaller scale.

A guide 51 has a slot running lengthwise thereof within which a pin 58 projects, said pin extending from the side of the staff at which the rack teeth are out. .That prevents rotation of the staff onits own axis and thus maintains the rack teeth in proper meshing relationship tothe pinion 52. a

ning from the case to the base in which is drilled an opening of the same diameter as the internal diameter of the sleeve. The wire cord is also guided'within the slot cutin the element. 51.

Different weights 33may be used depending upon the size of 'cords to be tested and other considerations, these weights being quickly he'- tachable in a manner similar to weights used for platform type scales. In some tests it may not be desirable to vary or control the temperature or I humidity of the atmosphere 'towhich the cords-are subjected.- If it is important, those factors are controllable by circulating heated air through the upper compartment and controlling the humidity of that air in a maner not necessarily described in this application.

Cords may be subjected to elongation over any prescribed period of time and, as before stated, the apparatus may be used for testing cords or strands of any known material. In this specification a more or less specific description has been given as applied to a preferred embodiment of the invention, but variations and modifications will occur to those skilled in the art and obviously would fall within the scope of the invention as originally conceived. The invention is defined in the appended claims.

What is claimed is:

1. A dial gauge having a case having a face, a base, a central stafi positioned in said case and having one end projecting therefrom, and indicating means at the face of the case and movable in accordance with movements of the staff to indicate the lineal distance between the projecting end of the stafi and the base, said staff having rack teeth out therein, a pinion meshing With said rack teeth, a pivot on which said pinion is fixed to rotate, a drum on said pivot, a fine strand wrapped about the drum and having attached thereto a Weight for counter-balancing the staff, guiding means for the strand and a tube in which said weight is housed.

2. A dial gauge having a case having a face, a base, a central stafi positioned in said case and having one end projecting therefrom, and indieating means at the face of the case and movable n accordance with movements of the stafi to ndicate the lineal distance between the projectmg end of the staff and the base, said stafi having rack teeth out therein, a pinion meshing with said rack teeth, a pivot on which said pinion is fixed to rotate, a drum on said pivot and rotatable therewith, said drum having connected thereto a fine WlIe strand, means for guiding said strand as it depends from said drum, a well defined by a sleeve and an opening in the base, said wire strand having a weight attached at its lower end, the said Weight being movable vertically inthe well but not contacting the sides thereof, said Weight acting as a counter-balance for the central staff and its attached parts.

GEORGE P. BOSOMWORTH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS FOREIGN PATENTS Country Date The Netherlands June 18, 1922 Number Number 

